I noticed you had no replies, I will try and help...
Firstly, you need Tableau Server, enabling offline snapshots is configured at the Site level.
More via >> Navigate Tableau Server Then >> Server Administration Pages
Somewhere else I found this:
And this is the option in Tableau Server (remember at the site level)
That's all I got, I haven't used it yet... I assume its to be used in conjunction with the Tableau App
Hope something there is helpful